1. Field of the Invention
This invention relates to an agent and a process for fatliquoring leather and skins, in which the fat liquoring agent used is an amphoteric surfactant produced by the condensation of C.sub.6-22 -fatty acids (FA) or the corresponding fatty acid esters with certain aminoalkyl alkanolamines.
2. Statement of the Related Art
The production of amphoteric surfactants of the type useful in this invention is described in pending U.S. application Ser. No. 485,610 of Oct. 18, 1983, incorporated herein by reference, and which claims priority from now published German patent application No. 30 18 201, according to which they are synthesized by condensation of C.sub.6-22 fatty acids with aminoalkyl alkanolamides corresponding to the formula I given below in a mol ratio of 1:1-1.5, and subsequent alkylation with vinylog compounds. The alkylation products may contain optionally quaternized, nitrogen atoms according to their structure and the degree of reaction. Because the condensation products of fatty acid and aminoalkyl alkanolamine generally contain a more or less high percentage of diamide, the alkylation is preferably preceded by an alkaline pretreatment to convert the diamide into the monoamide. This leads in the subsequent alkylation step to improved amphoteric surfactants characterized in particular by increased stability in storage.